Multi-mode electromechanical variable transmission

Patent metadata

Field	Value
Publication number	US-2016288780-A1
Application number	US-201514792535-A
Country	US
Kind code	A1
Filing date	Jul 6, 2015
Priority date	Feb 17, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

A vehicle includes an engine, a drive axle, a multi-mode transmission, and a controller coupled to the multi-mode transmission. The multi-mode transmission includes a first gear set having a first planetary gear carrier and a second gear set having a second planetary gear carrier, the first planetary gear carrier and the second planetary gear carrier being rotatably coupled, a first motor/generator coupled to the first gear set, a second motor/generator coupled to the second gear set and selectively coupled to the engine, a brake positioned to selectively limit a rotational movement of a ring gear of the second gear set when engaged, a first clutch, and a second clutch. The controller is configured to selectively transition the multi-mode transmission between a mid range mode of operation and a high range mode of operation via an intermediate shift mode of operation.

First claim

What is claimed is:

1 . A vehicle, comprising:
an engine; a drive axle; a multi-mode transmission including:
a first gear set having a first planetary gear carrier and a second gear set having a second planetary gear carrier, wherein the first planetary gear carrier and the second planetary gear carrier are rotatably coupled;
a first motor/generator coupled to the first gear set;
a second motor/generator coupled to the second gear set and selectively coupled to the engine;
a brake positioned to selectively limit a rotational movement of a ring gear of the second gear set when engaged;
a first clutch selectively rotationally coupling the first planetary gear carrier and the second planetary gear carrier to the drive axle when engaged; and
a second clutch selectively rotationally coupling the second motor/generator to the engine when engaged; and
a controller coupled to the multi-mode transmission and configured to selectively transition the multi-mode transmission between a mid range mode of operation and a high range mode of operation via an intermediate shift mode of operation.

2 . The vehicle of claim 1 , wherein the controller is configured to selectively transition the multi-mode transmission into the intermediate shift mode of operation in response to the second motor/generator having a rotational speed that is substantially equal to a rotational speed of the engine.

3 . The vehicle of claim 1 , wherein the controller is configured to selectively transition the multi-mode transmission into the intermediate shift mode of operation in response to the difference between a rotational speed of the second motor/generator and a rotational speed of the engine falling below a threshold level.

4 . The vehicle of claim 1 , wherein the engine is coupled to the drive axle through a fixed ratio when the multi-mode transmission is selectively reconfigured into the intermediate shift mode of operation.

5 . The vehicle of claim 1 , wherein the controller is configured to:
engage the brake and the first clutch to selectively reconfigure the multi-mode transmission into the mid range mode of operation; and engage the second clutch to couple the second motor/generator to the engine and maintain engagement of the brake and the first clutch to selectively reconfigure the multi-mode transmission from the mid range mode of operation to the intermediate shift mode of operation.

6 . The vehicle of claim 5 , wherein the controller is configured to:
disengage the brake to selectively reconfigure the multi-mode transmission into the high range mode of operation from the intermediate shift mode of operation and thereby complete a transition between the mid range mode of operation and the high range mode of operation.

7 . The vehicle of claim 1 , wherein the engine is coupled to the first motor/generator during the mid range mode of operation and provides a rotational input thereto, the mid range mode of operation facilitating a mid range output speed operation of the vehicle, and wherein the first motor/generator is configured to generate electricity in the mid range mode of operation that powers the second motor/generator to provide a mechanical output to the drive axle.

8 . The vehicle of claim 7 , wherein the engine is coupled to the second motor/generator during the high range mode of operation and provides a rotational input thereto, the high range mode of operation facilitating a high range output speed operation of the vehicle.

9 . The vehicle of claim 1 , wherein the controller is configured to automatically transition the multi-mode transmission out of the intermediate shift mode of operation in response to at least one of an elapsed shift time, a traveled shift distance, a change in a speed of the engine, and a request.

10 . The vehicle of claim 9 , wherein the controller is configured to:
automatically transition the multi-mode transmission out of the intermediate shift mode of operation and into the high range mode of operation by disengaging the brake in response to the engine exceeding a threshold speed; and automatically transition the multi-mode transmission out of the intermediate shift mode of operation and into the mid range mode of operation by disengaging the second clutch in response to the engine falling below a threshold speed.

11 . A drive system for a vehicle, comprising:
a first gear set including a first sun gear, a first ring gear, a first plurality of planetary gears coupling the first sun gear to the first ring gear, and a first carrier rotationally supporting the first plurality of planetary gears; a second gear set including a second sun gear, a second ring gear, a second plurality of planetary gears coupling the second sun gear to the second ring gear, and a second carrier rotationally supporting the second plurality of planetary gears, wherein the first carrier is directly coupled to the second carrier; a first electrical machine coupled to the first gear set; a second electrical machine coupled to the second gear set; a connecting shaft coupling an engine to the first gear set; a brake positioned to selectively limit a rotational movement of the second ring gear when engaged; a first clutch selectively rotationally coupling the first carrier and the second carrier to a driveshaft output of the vehicle when engaged; and a second clutch selectively rotationally coupling the second electrical machine to the connecting shaft and the engine when engaged.

12 . The drive system of claim 11 , wherein the drive system is selectively reconfigurable into an intermediate shift mode of operation, wherein the intermediate shift mode of operation facilitates transitioning the drive system between a first mode of operation and a second mode of operation.

13 . The drive system of claim 12 , wherein the brake, the first clutch, and the second clutch are engaged in the intermediate shift mode of operation.

14 . The drive system of claim 13 , wherein the second clutch is disengaged to transition from the intermediate shift mode of operation to the first mode of operation, and wherein the brake is disengaged to transition from the intermediate shift mode of operation to the second mode of operation.

15 . The drive system of claim 14 , wherein the first mode of operation is a mid range mode of operation configured to facilitate mid range output speed operation of the vehicle, wherein the engine is coupled to the first electrical machine during the mid range mode of operation and provides a rotational input thereto, and wherein the first electrical machine is configured to generate electricity in the mid range mode of operation that powers the second electrical machine to provide a mechanical output to the driveshaft output of the vehicle.

16 . The drive system of claim 15 , wherein the second mode of operation is a high range mode of operation configured to facilitate high range output speed operation of the vehicle, wherein the engine is coupled to the second electrical machine during the high range mode of operation and provides a rotational input thereto.

17 . The drive system of claim 12 , wherein the drive system is transitioned into the intermediate shift mode of operation in response to the second electrical machine having a rotational speed that is substantially equal to a rotational speed of the connecting shaft.

18 . The drive system of claim 12 , wherein the drive system is transitioned into the intermediate shift mode of operation in response the difference between a rotational speed of the second

Assignees

• Oshkosh Corp

Inventors

• Shukla Deepak
• Kotloski Andrew J

Classifications

• B60K6/543

  the transmission being a continuously variable transmission · CPC title

• B60W30/19 Primary

  Improvement of gear change, e.g. by synchronisation or smoothing gear shift · CPC title

• B60W10/08

  including control of electric propulsion units, e.g. motors or generators · CPC title

• B60W10/105

  of electric type · CPC title

• B60W20/10 Primary

  Controlling the power contribution of each of the prime movers to meet required power demand · CPC title